Interference :(

[Pataforce8 10+ year member]

My headunit is a Kenwood eXcelon X794. I'm pretty sure the interference is caused by the headunit because the interference is fairly loud and it only occurs on one channel, my front left. If I pull the signal out of the the front left pre-amp then the interference goes away.

However, the interference is intermittent. Once I pulled the front left RCA and tested and re-assembled, the interference was gone. It stayed gone for a good 5 hours. Then I got off work and started my car and it was back, just as loud as before.

My only thought is too maybe ground those RCA's at the back of the head unit? I can figure why the interference would be intermittent.

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[All_Logix 10+ year member]

Try wrapping bare wire around the RCA shell and attaching it to the radios metal frame, I think there is a picture of what this looks like in the sticky for ground fixes... if that doesn't solve the problem I would check the RCA cable and make sure it isn't something to do with the shielding or a fracture in the cable. Just to rule it out, also make sure power wires are not REAL close to signal cables like RCA or speaker wire in long runs....if none of that gives you results...best to take the HU back, excelon is top notch in Kenwood, they shouldn't have that problem

 

[Pataforce8 10+ year member]

I can't take the HU back as it's discontinued //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif but over the weekend it was continuous enough that I had figured something had broken, and then I magically started up my car once and it hasn't come back since.

I will try grounding the RCA's....should I also ground the frame of the HU to the chassis? I'm kind of scared to tear back into since it has stopped for now.

 

[Kangaroux 5,000+ posts]

not necessary to ground to the chassis, just try grounding the RCA's. though if it's only one channel I suspect it may be a bad rca cable.

 

[Pataforce8 10+ year member]

It finally came back after several days of musical bliss.

I managed to pull the dash apart with it still interfering and I tried grounding the RCA to no avail. I then switched the front left and front right RCAs and bam the interference was in the front right speaker, so it's definitely occurring within the head unit. Also, it can't be a bad ground, because I have to head unit torn apart and all of the RCAs are grounded together by one big plate.

So, someone who knows a lot about amplifiers and circuits, what am I looking for? What within the headunit could go from blocking interference (the interference is definitely from the engine) to allowing tons of interference in simply from slamming the door too hard?

 

[Pataforce8 10+ year member]

Anyone?